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Howlett" , Andreas Larsson , "David S . Miller" , Huacai Chen , Alexander Gordeev , Gerald Schaefer , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 0/8] Stop special-casing hugetlb mappings in get_unmapped_area Message-Id: <20260627235512.787d09b15b3d2ff9441e604a@linux-foundation.org> In-Reply-To: <20260606035003.529685-1-osalvador@suse.de> References: <20260606035003.529685-1-osalvador@suse.de> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspam-User: X-Stat-Signature: xwbpphnujuhiugrxiuatmx8ije1hs1aw X-Rspamd-Queue-Id: 9651A1A0006 X-Rspamd-Server: rspam06 X-HE-Tag: 1782629714-310276 X-HE-Meta: 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 ak0z06LV 4IU3Dl2/On2lRNpo3u8ASeGhS1gWVr5EC7c/dZWk7Iu0fauR9r/aH/aQp5XLPqtQ+PWWQlqcbS7NqYgCA8iEud/G+HiFJYmj3GPK6tMGw+eQwgFQaVosE8hiLeu27eZUH4SPAQZ2Bfe4Ooab5241J0v7XT79WokSL7O3b+YBb8+niIQnWgoXr9VcBBfgpHHdOdkRADzQ8ixtkb+GjQ8iO+hkRdAiF8wYSGVQeG7GgW0OLynQXOav8Trvt5xuL4Y2Y+TWQ4n2zajohI/otH3zItnq4YzNi9QeX2HvDFClMYukIRpNxiLmYg+9kEgmo9XXXgbECHxIoM8Amnukg2ZqgOvZn3Ep2u8AWEVu15Kp8cTrWZ0k= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sat, 6 Jun 2026 05:49:55 +0200 Oscar Salvador wrote: > A regression was reported on AMD 15h Family for hugetlb mappings when 'align_va_addr' > is set [1]. It would be helpful to say right here that this regression results in a runtime BUG(). Helps get attention ;) > Historically, for hugetlb mappings we always ignored 'align_offset' in get_unmapped_area > functions, but after commit 7bd3f1e1a9ae ("mm: make hugetlb mappings go through > mm_get_unmapped_area_vmflags") that was no longer the case for x86. > > While we could fix that by work it around in x86 code, the truth is that the current > functioning of hugetlb mappings with get_unmapped_area functions is a bit clumsy, and > we can do better. > This patchset aims at two things: > > 1) Fix regression reported in [1] > 2) Stop special-casing hugetlb mappings in get_unmapped_area functions OK, so the offending commit was about 1.5 years ago. Do we want to fix -stable kernels? If so, can we start out with something minimal for backporting? And narrow down its Fixes:? The series was sent at an awkward time in the -rc cycle, which perhaps explains the lack of feedback. I suggest a refresh/retest/resend to help bring people up to speed. Sashiko has quite a lot to say - I hope some of it is useful? https://sashiko.dev/#/patchset/20260606035003.529685-1-osalvador@suse.de